Inverse Proportional Pressure-Relief Cart., Size Q max = l/min, p max = 35 bar Direct acting, electrically operated Description Compact construction for cavity type AL 3/-6 UNF Operated by a proportional solenoid Nominal pressure when solenoid de-energised (fail-safe function) 6 pressure ranges available All exposed parts, without solenoid coil, with zinc-nickel plating High pressure wet-armature solenoids The slip-on coil can be rotated, and it can be replaced without opening the hydraulic envelope With integral manual pressure setting Can be fitted in a line-mounting body inverse proportional pressure-relief valves are direct acting screw-in cartridges of sliding-spool design with a falling pressure/current characteristic and a 3/-6 UNF mounting thread. With these pressure-relief cartridges, the relief pressure is dependent on the electrical control signal and can be continuously varied. When the solenoid is de-energised (initial position), the relief pressure is the nominal pressure of the applicable spring range (failsafe function). Any pressure at port is additive to the valve setting at port, therefore port should preferably be connected directly to tank. In control mode, the relief pressure is inversely proportional to the change in the required value (amplifier output current). In order to obtain precise pressure settings over the whole of the required pressure range (optimum resolution), the pressure relief cartridges are available in six spring ranges. If a proportional solenoid is faulty, for example, the integral manual pressure setting enables the required pressure to be set mechanically. Inverse proportional pressure-relief cartridges are predominantly used in mobile and industrial applications to allow a pressure in hydraulic installations to be limited electro-proportionally. All external parts of the cartridge are zinc-nickel plated to DIN 5 979 solenoid coil are zinc plated, and are thus suitable for use in the harshest operating environments. The slip-on coils can be replaced without opening the hydraulic envelope and can be positioned at any angle through 36. If you intend to manufacture your own cavities or are designing a line-mounting installation, please refer to the section Related data sheets. Symbol 3 Technical data General characteristics Designation Design Mounting method Tightening torque Size Weight inverse proportional pressure-relief cartridge direct acting, electrically operated screw-in cartridge 3/-6 UNF Nm ± % nominal size..., cavity type AL.5 kg Reference: -P-585-EN-3 Issue: 3.7 /6
General characteristics Mounting attitude Ambient temperature range unrestricted (preferably vertical, coil down) -5 C +5 C Hydraulic characteristics Maximum operating pressure (p max ) - main port - port Maximum flow rate Nominal pressure ranges (p N ) Leakage flow rate Flow direction 35 bar 5 bar ) l/min 5 bar, 63 bar, bar, 6 bar, 3 bar, 35 bar. l/min = pressure range 5 bar / 63 bar. l/min = pressure range bar.5 l/min = pressure range 6 bar.3 l/min = pressure range 3 bar. l/min = pressure range 35 bar see symbols Hydraulic fluid HL and HLP mineral oil to DIN 5 5; for other fluids, please contact BUCHER Hydraulic fluid temperature range Viscosity range Minimum fluid cleanliness Cleanliness class to ISO 6 : 999-5 C +7 C 5 38 mm /s (cst), recommended...3 mm /s (cst) class 8/6/3 ) To prevent any pressure surges, port must be routed to tank with the least possible back-pressure. Any tank pressure acting at port is additive to the pressure setting at the main port. Electrical characteristics Supply voltage Control current Power consumption at max. control current Coil resistance R - cold value at C - max. warm value Recommended PWM frequency (dither) Hysteresis with PWM Reversal error with PWM Sensitivity with PWM Reproducibility with PWM V DC, V DC V = 6 ma, V = 8 ma max. 9.5 W V =.8 / V = 7.7 V = 7.5 / V = 3 Hz % I N % I N < % I N < % p N Switching time 6 9 ms (Solenoid ON) 6 ms (Solenoid OFF) These times are strongly influenced by fluid pressure, flow rate and viscosity, as well as by the dwell time under pressure. Relative duty cycle % Protection class to ISO 653 / EN 6 59 IP 65 Electrical connection 3-pin square plug to ISO / DIN 3 65 (standard) for other connectors, see Ordering code /6 -P-585-EN-3/3.7
Performance graphs measured with oil viscosity 33 mm /s (cst) p = f (I) Pressure adjustment characteristic (Q = l/min) 7 P3.ai p = f (I) Pressure adjustment characteristic (Q = l/min) 35 P35.ai 6 5 p N 63 bar 3 5 p N 3 bar p N 35 bar 3 p N 5 bar 3 6 8 5 6 7 8 I [ma] 6 p = f (Q) Pressure - Flow rate characteristic p N = 5 bar 3 P36.ai 8 6 Q [l/min] p = f (Q) Pressure - Flow rate characteristic p N = bar 8 6 P38.ai 6 8 5 Q [l/min] p = f (Q) Pressure - Flow rate characteristic p N = 3 bar 3 5 P.ai 5 5 p N 6 bar p N bar 3 6 8 5 6 7 8 I [ma] 6 p = f (Q) Pressure - Flow rate characteristic p N = 63 bar 9 8 7 6 5 3 P37.ai 8 6 8 Q [l/min] p = f (Q) Pressure - Flow rate characteristic p N = 6 bar 8 5 9 6 3 P39.ai 6 8 3 Q [l/min] p = f (Q) Pressure - Flow rate characteristic p N = 35 bar 35 3 P.ai 5 5 5 5 5 3 5 6 7 8 9 Q [l/min] 3 5 6 Q [l/min] -P-585-EN-3/3.7 3/6
5 Dimensions & sectional view 8 3/ 6 UNF M A = [Nm] % 3 7. 35. 35 8.3 3 M A =.7 [Nm] % 3 M A = [Nm] % B A M A = [Nm] % 6.3 77.8 Seal kit NBR no. DS-8-N ) Item Qty. Description O-ring no. 7 7.7 x.78 N9 O-ring no.. x.78 N9 3 O-ring 6. x. FKM Backup ring.7 x.5 x. FI75 IMPORTANT! ) Seal kit with FKM (Viton) seals no. DS-8-V Integral air-bleeding If necessary, air can be purged from these proportional pressure-relief cartridges by using the integral air-bleed screw (Item B). The procedure is as follows: A Protective cap B Air-bleed screw Steps:. Remove the protective cap.. Slacken the air-bleed screw approx. turns. 3. Switch the pressure-relief cartridge on/off several times until no more air bubbles escape.. Tighten the air-bleed screw (Ma = Nm %). 5. Fit the protective cap. /6 -P-585-EN-3/3.7
6 Installation information IMPORTANT! To achieve the proportional pressure-relief cartridge's maximum performance rating, fit the solenoid coil as shown (with the plug pins at the top). When fitting the cartridges, note the mounting attitude (preferably vertical, with coil down automatic air bleed) and use the specified tightening torque. No adjustments are necessary, since the cartridges are set in the factory. Only qualified personnel with mechanical skills may carry out any maintenance work. Generally, the only work that should ever be undertaken is to check, and possibly replace, the seals. When changing seals, oil or grease the new seals thoroughly before fitting them. To prevent any pressure surges, port must be routed to tank with the least possible back-pressure. Any tank pressure acting at port is additive to the pressure setting at the main port. 7 Manual pressure setting These inverse proportional pressure-relief cartridges are equipped as standard with an integral manual pressure setting. If a proportional solenoid is faulty, for example, this manual pressure setting enables the required pressure to be set mechanically. The manual pressure setting can also be used to make minor pressure adjustments directly at the system. IMPORTANT! Any changes to the manual pressure setting have a direct effect on the factory settings. Setting the pressure manually Steps:. Remove the protective cap.. Slacken the lock nut (3 A/F). 3. Unscrew (turn to left) the adjusting spindle ( A/F) until the required pressure is set.. Tighten the lock nut (3 A/F). 5. Fit the protective cap. C D E E D C Protective cap Lock nut (3 A/F) Adjusting spindle for pressure setting 3 M A = [Nm] ± % To reset the inverse proportional pressure-relief cartridges to their initial position (the factory setting), a constant flow rate and a pressure gauge that measures the pressure in the main port are needed. The pressure setting must not exceed the nominal pressure of the spring range in use. The procedure is as follows: Restoring the factory settings Steps:. Solenoid de-energised.. Remove the protective cap. 3. Slacken the lock nut (3 A/F).. Unscrew the adjusting spindle ( A/F) to its end-stop, then screw it in until the pressure on the gauge reaches the nominal pressure (p N ) of the spring range in use. 5. Tighten the lock nut (3 A/F). 6. Fit the protective cap. -P-585-EN-3/3.7 5/6
8 Ordering code D B D R B - L G - 35 - _ - 3 D _ D = pressure control valve B = pressure relief function D = direct acting R = proportional solenoid A... Q = standard model - see relevant data sheets Z... R = special features - please consult BUCHER = pressure function L = cavity type AL G = proportional solenoid, inverse type (pulling) 35 = pressure range 35 bar 3 = pressure range 3 bar 6 = pressure range 6 bar = pressure range bar 63 = pressure range 63 bar 5 = pressure range 5 bar = nominal size for pressure ranges 35 and 3 3 = nominal size 3 for pressure ranges 6 and = nominal size for pressure ranges 63 and 5 (blank) = NBR (Nitrile) seals (standard) V = FKM (Viton) seals (special seals - please contact BUCHER)... 9 = design stage (omit when ordering new units)... = voltage e.g. ( V) D = current DC (blank) = ISO / DIN 3 65 connection with mating plug (standard, IP 65) M = ISO / DIN 3 65 connection without mating plug for the following plug-variants, please consult Bucher: J = Junior Timer radial plug connection (IP 65) mating plug not supplied 9 Related data sheets Reference (Old no.) Description -P- (i-3) The form-tool hire programme -P-67 Cavity type AL -P-5 Amplifier unit for proportional valves (-channel) PBS - 3A -P-5 (P-3) Amplifier card, -channel for valves with one solenoid, type SAN-535 -P-7 Line-mounting body, type GALA (G 3/ ) info.ch@bucherhydraulics.com www.bucherhydraulics.com 7 by Bucher Hydraulics AG Frutigen, CH-37 Frutigen All rights reserved. Data is provided for the purpose of product description only, and must not be construed as warranted characteristics in the legal sense. The information does not relieve users from the duty of conducting their own evaluations and tests. Because the products are subject to continual improvement, we reserve the right to amend the product specifications contained in this catalogue. Classification: 3.35.3.35.35.3 6/6 -P-585-EN-3/3.7